[@Darth] 

I sort of disagree with the drawback a bit, depending on how realistically you play it. Jacer uses ammo amounts which means he has to be careful how many times he fires or he runs out of fire power. Not everyone does that really and so you get 'unlimited' ammo scenarios. Sadly that is only one drawback I can think of and one usually ignored, but it should still count as most mages, metahumans, etc don't have x amount shots they are able to use before the gun becomes nothing more than a decoration.